In this paper, we propose a system that allows users to move more safely in a variety of terrain using an electric wheelchair. Developing from previous paper “Intelligent Powered Wheelchair'” in which the ability to avoid obstacles using the laser sensor, wheelchair automatically avoid the obstacles using listening to the sound. Thus, this paper uses the sensor-based topography and controls the motor speed of the electric wheelchair according to the terrain. When normally using a power wheelchair to change fast speed suddenly, the electric wheelchair overturned, and the user happens to fall in the future. In this case, because of the center of gravity of the wheelchair due to a sudden change in the law of momentum maintaining, it occurs dangerous for users. In addition, if wheel chair does not pass through the flat terrain and to safely pass the terrain changed by controlling the motor speed in order to reduce speed slowly. The sensor was used as an acceleration sensor and a gyro sensor by using a Kalman filter to output a correct angular value. In this paper, by providing SOS service system help to receive quickly the displaying the location map, users can predefine if the button is clicked, or need urgent help. The user's location using a GPS signal and Google API was built in the smart phone, GPS’s information identify the location of the user. In addition, the user's locations and user’s data are saved on the server that is responsible for managing in real time, if new users request and receive the notification signal analysis, they can ask the people who previously registered via message or email.